Underlining the importance of aviation in economic development of countries, president Pratibha Patil on Monday sought "flexible business modules" for expansion of the aviation industry.

"Innovative and flexible business modules may be evolved, enabling greater connectivity between countries to promote people-to-people contacts, as well as trade and business.

"To achieve this, governments must continually negotiate new bilateral treaties, to allow for and expand access to new and emerging markets for their carriers," Patil said inaugurating the fourth International Civil Aviation Negotiation (ICAN) conference in Mumbai.

She said airlines could act as "goodwill ambassadors" to connect people across the globe.

"Flying is no longer the prerogative of a few privileged, but an option for an increasingly broader section of society. Airlines could be goodwill ambassadors to bring nations and peoples together," the President, who is on a two-day visit of Mumbai, said.

The rapidly expanding aviation sector handles 2.5 billion passengers across the world in a year; moves 45 million tonnes of cargo through 920 airlines, using 4,200 airports and deploying 27,000 aircraft.

"Such a large scale global operation requires that experts of Member States of International Civil Aviation Organisation must gather frequently, to evolve consensus and co-ordination on various issues to ensure a universally safe and secure international aviation sector," she said.

Taking note of the rapid growth in the aviation industry in recent past, Patil said the country plans to expand the airport network and provide connectivity to tier II and III cities in the next five years.

"We are also looking at further developing several airports in state capitals, in tourist centres and business and commercial centres. In the city side of these airports the private sector will be invited for developing hotels, shopping complexes, cargo, parking lots, and food courts, among others," Patil said.

The President also asked the investors to become partners in the process of making airports friendlier for the traveller.

"There is a sea change from 500 departures per week in the country in 1994 before deregulation, to nearly 15,000 departures daily - a 30 times jump. Today, 87 foreign airlines fly to and from India and 5 Indian carriers fly to and from 40 countries," she said.

In the last decade, domestic air traffic has quadrupled from 13 million to 52 million and international traffic more than tripled to 38 million.

"A similar trend is observed in the cargo sector," the President said.

Today in India, about 60 per cent of air traffic is being handled in airports under the Public Private Partnership model at Delhi, Mumbai, Hyderabad and Bangalore and the rest 40 per cent, is with airports owned and operated by the Airports Authority of India.

During the period from 2005 to 2010, USD 10 billion has been invested in airport development in the country.

"In next five years, we plan to expand the airport network and provide connectivity to tier II and III cities. In Metro cities where the existing airport cannot accommodate future growth, a second airport is being planned in the same city. New Mumbai is a case in example," she said.